1. Field of Invention
The present invention relates to a method for manufacturing the active carbon air purification product, and more particularly to a method for manufacturing photocatalyst multifunctional dust-free active carbon color ball which is adapted for indoor air pollution control and purification.
2. Description of Related Arts
Active carbon is a kind of carbon-based adsorption material with abundant pore structure and huge specific surface area. It has some characteristics, such as strong adsorption capacity, good chemical stability, high mechanical strength, and easy regeneration, and is widely used in industry, agriculture, national defense, transportation, medicine and health, environmental protection and other fields. With the development of society and improvement of living standards, the demand for active carbon has been on the rise in recent years. Especially in recent years, with the ever-increasing requirement of human being's survival environmental protection, more and more active carbons have been required at home and abroad. Moreover, with the improvement of people's environmental protection consciousness and demand standard, the higher and broader demand for the performance of active carbon has been made. Therefore, the new development of application performance of active carbon is needed.
In prior art, the activating treatment of active carbon increases the microporous surface of active carbon for improving the adsorption property thereof. China patent application No. 00105398.1, entitled “Coated Active Carbon”, discloses a material combination containing active carbon, wherein the active carbon shows the initial, pre-coating butane activity and butane working ability, and its surface is coated with a layer of continuous polymer membrane which is adapted for basically eliminating the material loss of active carbon caused by dust, wherein coated active carbon material shows that the last, after-coating butane activity and butane working ability are at least 90% of the initial, pre-coating butane activity and butane working ability respectively. This invention can avoid the product loss caused by active carbon pulverization and other commonly seen problems which relate to the final use of product.
Active carbon is an adsorption material using carbon as the main ingredient, and has a complicated structure. It is not like graphite and diamond to have the molecular structure with carbon atoms arranged in a regular pattern. Also, it is not like carbonaceous matter to have the complicated macromolecular structure. It is generally believed that active carbon has a pore structure which is formed by arranging microcrystalline similar to graphite in accordance with the whorl-shaped structure and strongly cross-linking among microcrystallines. The pore structure of active carbon relates to raw materials and production processes. The pore of active carbon is made up of macropore, mesopore and micropore. The diameter of the macropore is in the range of 50 nm and 200 nm, that of the mesopore is in the range of 2 nm and 50 nm, and that of micropore is smaller than 2 nm. The above pore diameters will adsorb the corresponding molecular sizes respectively. If the molecular size is larger than the pore diameter, the molecule will not enter the pore due to the molecular function, so there is no adsorption function. If the molecular size is approximately equal to the pore diameter, the molecular diameter corresponds to the pore diameter, so the adsorbent strongly captures the adsorption molecules, which is adapted for adsorbing at low concentration. If the molecular size is far less than the pore diameter, the adsorbed molecule is easily desorbed, has a rapid desorption speed and a small amount of adsorption at low concentration. Therefore, considering the adsorption performance, the actual size of microporous adsorbent should be equal to gas phase adsorption molecule size or smaller than micropore diameter.
Accordingly, it is not difficult for us to know the reason, that the adsorption ability active carbon acting on water molecule, benzene, ammonia and other harmful toxic small molecules is weak, is fewer micropores have the diameter smaller than 1 nm. The diameter of micropore of common active carbon is generally in the range of 1 nm and 2 nm, and the number of micropores is about ⅓ of that of total pores. However, this micropore diameter is too large for the small molecule with the diameter of 0.2 nm to 0.6 nm. Therefore, common active carbon, weakly adsorbing water molecules, benzene, ammonia and other harmful toxic small molecules, is difficult to develop in indoor air purification.